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CHAPTER 1
INTRODUCTION
1.1 Project title
The ergonomic assessment in manufacturing industries
1.2 Background of project
Vibration appears as an integral part of our everyday live such as cars, trucks, and motorcycles we feel vibration, washer machine and dryers vibration, lawn mowers
vibration, powered hedge clippers and brush cutters vibration, power boats vibration, powered shop tools vibration. An example at working area are machinery vibration,
lift trucks vibration, pneumatic and electrically powered tools all vibration, and the list goes on and on. For most part, little is thought about vibration since it is so
common until something happens to make us take notice.
Vibration refers to six directional motion of an object. There are actually up to six directions at any one point Bridger,2009 front to back, side to side, up or down
and three corresponding rotation, pitch, yaw and row. What we see with our eyes as an object moves is called displacement. What we do not see is the object‟s speed, or
velocity, the time rate to change of a moving object. Nor do we see acceleration, which is the time rate of change of speed of the moving object. Rotation is not
measured in human vibration work.
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For our information, be aware that there are some 8 million workers in the U.S alone that are occupationally exposed to vibration Bridger,2009 of which 7 million
exposed to whole body vibration WBV and 1 million are exposed to harm arm vibration HAV. The medical effect of WBV and HAV is not same.
Whole body vibration WBV or head to toe vibration is usually experienced by
operator of truck, buses, locomotive, lift truck, heavy equipment operation, farm vehicle operation, overhead cranes and found near vibrating machinery such as
punch presses or mould shakeout areas in foundries. In this project, the heavy equipment operation stamping machine had been choose to do analysis because of
this part more relate with our studies.
Studies of disease in large worker population and laboratory studies have
indicated that WBV exposure is associate with various musculoskeletal disease including but not limited to low back pain, degenerative inter vertebral disc disease,
and herniated and slipped discs. In addition, some studies show that female exposed to WBV have additional gynaecological risks especially during pregnancy
Waldemar, 1998.
Some medical consequences of WBV exposure appear as cumulative trauma disorders CTDs, where WBV exposure is experienced by the worker with no
apparent difficulties for an extended period of time. Then, problems such as a slipped disc might occur for no apparent reason or from an innocuous event like leaning over
to pick up a light object. Research work, in the United States and elsewhere is seeking to elucidate these actual injury mechanisms Sharawan, 2008. WBV
exposure can cause both safety and health problem.
The „Vibration Directive‟ Directive 200244EC sets minimum standards for
controlling the risks from whole-body vibration. The Vibration Directive requires that member states of the European Union implement national legislation to
implement the requirements of the Directive by 6th July 2005. National legislation may apply more favourable provisions than those required by the Directive, and
should not reduce the protection afforded to workers by any pre-existing national legislation. refer Appendix B
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1.3 Problem statement
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